Experimental study on self-healing and mechanical properties of sisal fiber-loaded microbial concrete

Abstract

Microbial concrete can make cracks self-healing, but the high alkalinity in concrete is not conducive to the survival and reproduction of microorganisms. In this study, using the porosity of the sisal fiber surface, microorganisms were immobilized on the sisal fiber, and the effects of several other microbial incorporation methods on the performance of self-healing concrete were compared. The fiber-loaded microbial concrete had the best self-healing effect, with a maximum self-healing width of 1.32 mm at 28 days. Splitting tensile strength is 28.7% greater than normal concrete, while compressive strength is 21.8% greater. The water absorption of sisal fiber enhanced the chloride permeability by 25.7%. Via microscopic examination, it was revealed that sisal fibers loaded a significant number of microorganisms and formed a large amount of calcium carbonate precipitation on the surface. Fiber-loaded microbial concrete’s elastic modulus and vickers hardness were 13% and 6% higher than normal concrete, respectively.